Multiple-bend metal-bending machine



June 19, 1951 B. GREEN MULTIPLE-BEND METAL BENDING MACHINE 7Sheets-Sheet 1 Filed June 12, 1948 (5 5- Gas-EN BY FM 8 7/ fir June 19,3951 L. B. GREEN MULTIPLE-BEND METAL BENDING MACHINE 7 Sheets-Sheet 2Filed June 12, 1948 &

INVENTOR. .45: 5. GAEE/Y BY 2 Z 5 firroe/wsys June 19, 1951 B. GREENMULTIPLE-BEND METAL BENDING MACHINE '7 Sheets-Sheet 5 Filed June 12,1948 fly-3 INVENTOR. 55 5. Giff/V zgmj mam g June 19, 1951 B. GREENMULTIPLE-BEND METAL BENDING MACHINE 7 Sheets-Sheet 4 Filed June 12, 1948INVENTOR. 66 5. 6195:

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June 19, 195] L. B. GREEN MULTIPLE-BEND METAL BENDING MACHINE Filed Jun12, 1948 7 Sheets-Sheet 5 .4 9N4 l 777/ MQ w l L l w Tm IIILT L. B.GREEN MULTIPLE-BEND METAL BENDING MACHINE June 19, 1951 '7 Sheets-Shet 6INVENTOR [5 8. GREAW Wyn 29 Filed June 12, 1948 June 19, 195] 1.. B.GREEN MULTIPLE-BEND METAL BENDING MACHINE 7 Sheets-Sheet 7 Filed June12, 1948 .N m 3 um N 15 a 0 E f 2 Patented June 19, 1951 UNITED STATESPATENT OFFICE MACHINE Lee B. Green, Lakewood, Ohio Application June 12,1948, Serial No. 32,657

This invention relates to bending machines of the kind used to formmetal workpieces to desired shapes by performing bending operationsthereon and, more particularly, this invention relates to an improvedconstruction for a bending machine of this type.

The bending machines of this kind which have been proposed heretoforehave, so far as I am aware, been adapted for forming in any one bendingoperation only a single bend in a workpiece or, at most, a pair of bendsas in my earlier Patent No. 2,287,933, granted June 30, 1942. To bend anelongated workpiece to polygonal form with any of the machinesheretofore available has required separate bending operations to beperformed in succession on the workpiece with a shifting of theworkpiece from one position to another and a reclamping of theworkpiece, between the successive bending operations. Because of thelimitations of these prior bending machines it has not been possible,heretofore, to bend elongated workpieces to polygonal form withsatisfactory accuracy nor in a rapid and. economical manner.

For use in certain manufactured metal products, it is desirable to forman elongated metal workpiece having one or more longitudinal flanges toa polygonal shape to constitute a housing, container body or othermember in which the flange or flanges of the workpiece provide anin-turned flange at one or both ends of such member. To accomplish thisthe workpiece must be bent at spaced points therealong by bending theweb portion out of its own plane and simultaneously bending the flangeportions within their own planes. So far as I am aware, no metal bendingmachine has been designed heretoforewhich is capable of carrying outsuch bending of a flanged workpiece to polygonal shape in one bendingoperation. Moreover, I am not aware of any prior bending machine inwhich two bends can be formed in a given portion of a flanged workpieceas successive steps of a single bending operation and in which thebending of the flange portions in their own planes is accomplishedwithout wrinkling or buckling of the metal. v

As one of its objects, this invention provides an improved bendingmachine by which the bending of a metal workpiece, or a longitudinallyflanged metal workpiece, to a desired shape can be carried outaccurately and in a rapid and economical manner.

Another object of the invention is to provide an improved bendingmachine in which the 20 Claims. (Cl. 153-39) forming of a metalworkpiece to a polygonal shape can be carried out' as a single bendingoperation so that it will only be necessary to place the workpiece inthe machine and subsequently remove the poly onally shaped article andno intermediate handling or reclamping of the workpiece betweensuccessive bending steps will be necessary.

A further object is to provide an improved machine of this characterhaving a die unit embodying multiple anvil die members and in whichmultiple bends, for example quadruple bends, are formed in the workpieceby bending the same around such die unit as a single bending operation.

Still another object is to provide an improved bending machine of thecharacter mentioned having a swinging wing which carries a plurality ofbendingdies adapted to form a plurality of bends in a metal workpiece,or in a longitudinally flanged metal workpiece, as successive steps of asingle bending operation.

Yet another object is to provide an improved bending machine of thischaracter having a die unit embodying multiple anvil die members andalso having a pair of wings each carrying a plurality of bending dies,and in which the wings are adapted to swing toward the die unit andcause the bending diesto form a plurality of bends in a metal workpiece,or in a longitudinally flanged metal workpiece, as successive steps of asingle bending operation.

As another of its important objects, this invention provides an improvedbending machine of the type embodying an anvil die means and a bendingdie, means rockable around said anvil die means for bending a metalworkpiece, or a longitudinally flanged metal workpiece, therearound andin which one portion of the bending die means is carried by a swingingmain wing and another portion of the bending die means is carried by anauxiliary wing which is movable relative to the main wing.

Still another object is to provide an improved bending machine of thecharacter mentioned in which the auxiliary wing is pivotally mounted onthe main wing and forms an extension thereof and is actuated by a powerdevice also carried by the main wing.

As a further'object this invention provides an improved bending machinehaving an anvil die and a bending die rockable around the anvil die bythe action of a swinging wing for bending a metal workpiece around theanvil die, and in which the bending die is mounted on the wing so 3 asto have substantially parallel movement, preferably sliding movement,relative thereto.

Yet another object is to provide an improved bending machine having ananvil die unit embodying anvil die members disposed in a polygonalarrangement and also having bending die means rockable around the anvildie unit so as to bend a metal workpiece, or a longitudinally flangedmetal workpiece, therearound to a polygonal shape by forming a pluralityof bends in the workpiece as successive steps of a single bendingoperation.

A further object is to provide such an improved bending machine in whichthe anvil die unit is contraotable to facilitate the removal of thepolygonally shaped workpiece therefrom.

Still another object is to provide an improved bending machine in whichan anvil die unit embodying a plurality of anvil die members disposed ina polygonal arrangement is adapted for clamping engagement with aworkpiece and in which bending die means rockable around the anvil dieunit for bending the workpiece to pclygonal shape therearound isactuated, in part, by swinging main wings and, in part, by swingingauxiliary wings carried by the respective main wings.

The invention can be further briefly summarized as consisting in certainnovel combinations and arrangement of parts hereinafter described andparticularly set out in the claims hereof.

In the accompanying sheets of drawings,

Fig. 1 is a front view partly in section of a bending machine embodyingthe present invention, the view being taken substantially as indicatedby section line II of Fig. 2;

Fig. 2 is a plan view of the machine but with the anvil die unitomitted;

Fig. 3 is a transverse vertical section taken substantially on theirregular section line 3-3 of Fig. 2;

Fig. 4 is a partial longitudinal vertical section taken on line 4-4 ofFig. 3 and showing the bending of the workpiece to polygonal shapenearly completed;

Fig. 5 is a partial longitudinal vertical section corresponding with aportion of Fig. l, but showing the same on a larger scale;

Fig. 6 is a partial transverse vertical section taken through themachine adjacent the front thereof at approximately the longitudinallocation indicated by section line 6-6 of Fig. 5;

Fig. 7 is a partial vertical section taken through the machine adjacentthe rear thereof at approximately the longitudinal location indicated bythe section line 'l-I of Fig. 5;

Fig. 8 is a transverse vertical section corresponding with the portionof Fig. 3 which shows the anvil die unit, but illustrating such unit ona larger scale;

Fig. 9 is a partial transverse vertical section taken through one of thepivots of an auxiliary wing as indicated by section line 9-9 of Fig. 5;and

Fig. 10 is a perspective view, with portions broken away, showing aworkpiece which has been bent to polygonal shape by the improvedmachine.

As shown in the drawings, the improved bending machine I0 is providedwith a frame II having a longitudinally extending bed portion I2 andalso having an upright portion I3 located at one side of the bed portionI2 at an intermeextending front and rear ways I4 and I5 on which a pairof longitudinally spaced frame sections I6 and I! are mounted and arelongitudinally adjustable. The upright frame portion I3 has a pair ofspaced vertical ways I8 and I9 thereon on which is mounted a verticallymovable diecarrying slide 20.

The die slide 20 provides a movable mount for an anvil die unit 2I whichwill'be described in greater detail hereinafter and which comprises, ingeneral, a die carrier 22 in the form of an elongated bracket extendingtransversely of the machine above the adjacent ends of the framesections I6 and I1 and a group of correspondingly elongated anvil diemembers 24, 25, 26 and 21 which have curved working faces and aredisposed in a polygonal arrangement and movably mounted in such diecarrier. The die carrier 22 is attached to the die slide 20 as by meansof the bolts 29 which engage in the T-slots 30 of the slide.

The die slide 20 is adapted to be moved downwardly on the upright waysI8 and I9 by a suitable power device such as the cylinder 3| (see Figs.2 and 3) mounted on the upright frame portion I3 by having its upper endconnected with a lug I3 of such frame portion by means of the pivot pin32. The cylinder 3| is a doubleacting cylinder adapted to be suppliedwith liquid under pressure, or other suitable motive fluid, and has apiston rod 33 projecting from the lower end thereof and connected to atransverse bar portion 34 of the die slide 20. The bar portion 34extends between, and has its ends connected to, the rearwardlyprojecting vertical flanges 2i! of the die slide. Suitablecounterbalancing means may be provided for the slide 20, such as thetension spring 35, having its upper end anchored on the frame I I as bymeans of the eye-bolt 36 and its lower end attached to the projectinglug 31 of the slide.

The frame sections I6 and I! are box-like structures provided at theiradjacent ends with upright walls 39 and 40 which carry table portions 39and 40 (see Figs. 1 and 5) extending transversely of the machine beneaththe anvil die unit 2]. Work clamping dies 4| and 42 of a generally fiatshape are mounted in fixed relation on the table portions 39 and 4th andare adapted to be clampingly engaged by portions of the anvil diemembers 24 and 26 when the die unit 2| is moved downwardly by the powercylinder 3|. Fig. 4 of the drawings shows an elongated workpiece 43 inthe machine and having an intermediate portion thereof clamped at spacedpoints by the action of the anvil die members 24 and 26 in cooperationwith the clamping die members M and 42.

As will be explained in greater detail hereinafter, the portions of theworkpiece 43 which extend in opposite directions from the intermediateportion which is clamped between the anvil die members 24, 26 and theclamping die members 4I 42 are bent upwardly and around the die unit 2Ito form the workpiece into the polygonal part or article illustrated inFig. 10. In carrying out this operation longitudinally spaced portionsof the workpiece 43 are bent around the anvil die members 24 and 25 toform the bends 24 and 25 and other longitudinally spaced portions of theworkpiece are bent around the anvil die members 26 and 21 to form thebends 26 and 21. The bending of the longitudinally spaced portions ofthe workpiece around the anvil die members 24 and 25 is accomplished bya pair of generally flat main and auxiliary bending dies and 46 and thebending of the other longitudinally spaced portions of the workpiecearound the anvil die members 26 and 21 is accomplishedby another membersby generally fiat auxiliary clamping dies 49 and 50.

' The bending dies 45 and: 46 together with the clamping die 49constitute one group of die'members which is carried by a-main wing andthe bending dies 41 and 48 together with the clamping die 56 constituteanother group'of die members which is carried by a similar main wing 52.The auxiliary bending dies 46 and 48 are carried respectively byauxiliary wings 53 and 54 which, as explained in greater detailhereinafter, are mounted on the main wings 5| and 52 for swingingmovement relative thereto. The main wings 5| and 52 are located,respectively, in the frame sections I6 and I! and are pivotally mountedthereon for swinging movement upwardly and toward the anvil die unit 2|from opposite sides thereof, as shown in Fig. 4. The auxiliary wings 53and 54 constitute extensions of the main wings and are adapted to swinginwardly and downwardly toward the anvil die unit 2|, as is also such asthe wing 5|, and for only one of the auxil" iary wings, such as theauxiliary wing 53. Since,

as explained above, the constructions are the same for the main wings 5|and 52 and the mechanisms associated therewith, and are the same for theauxiliary wings 53 and 54 and the mechanisms associated therewith, thesame reference char-'- a'cters have been applied to corresponding parts.

1 The main wing 5| comprises a substantially rigid bracket-likestructure having a hollow body portion 55 extending transversely of themachine and a pair of laterally spaced front and rear arm portions 56and 51 extending longitudinally of the machine. The arms 56 and 57 areintegrally connected with or welded to the transverse hollow bodyportion 55 and are also connected with: the

latter by means of the angular bracing webs 58.

The wing 5| is also provided with a pair of spaced front and rear arms59 and 68 by which it is pivotally mounted on the frame section l6. Asshown in Figs. 2 and 6, the wing 5| can be pivotally connected with theframe section [6 by providing: the

latter with a pair of front and rear bosses 6|land 62 carrying front andrear pivot members 63 "and 64 having shouldered portions 65'on which thearms 59 and 66 of the wing are pivotally mounted. The, pivot members 63and 64 are retained in the bosses 6| and 62 as by means of the clampingbolt 63*- and washer 63 (see Fig. 6).

"The main wing 5| is also provided with a pres-. sure roller 66 locatedin the hollow body portion 55 adjacent the top'thereof and having itsends ivu d in bearing mb s i i-whi h a e 6 plies pressure totheworkpiece through this die ablymounted in the wing so as to adapt theroller for movement toward and away from the axis of the pivot members63 and 64. springs 68 mounted in the wing act on the bearing members 61and normally urge the roller 66 toward the pivot axis of the wing.

The main bending die .45 is located between the :arms 56 and 66 of themain wing 5| and is mounted on a carrier in the form of a die plate"GB-which extends transversely of the machine.

and has-a beveled edge portion I0 shaped for cooperating engagement withthe beveled portion H of the adjacent edge of the table 89 when thebending die is in its initial or work-receiving position. The die plate69 is provided with front andrear rack elements 12 and 73 on the upperside; thereof which mesh with front and rear arcuate gear elements orsectors 14 and 15. The gear sectors 14 and 15 are provided in fixed re-.lation on the frame H and, in this instance, are carried by front andrear links 16 and 11 by which theadjacent ends of the frame sections l6and I! are connected together. The dieplate 69, with the main bendingdie 45 thereon, is supported by the roller 66 and the racks l2 and 13 ofthe die plate. 69 are held in mesh with the gear sectors 14 and 15 bythe action of the springs 68 which press-the roller 66 against the underside of the die plate. The die plate 69 is also provided on the underside thereof with front and rear racks i8 and the roller 66 is providedadjacent its ends with gears 19 which mesh with these racks (see Fig.6). The gears 19 are mounted on reduced end portions 66 of the rollers66 and are connected for rotation ther withby means of the keys 66 Theaction of the springs 68 also holds the gear 19 of the roller 66 in meshwith the racks 18 of the die plate.

The main bending die 41 is supported by another such die plate 69.

The auxiliary clamping die 49 is mounted on a die carrier 86 which issupported by the arms 56 and 51 of the main wing 5|. The die carrier 86is a plate-like member which is adjustable on the main wing 5| in adirection longitudinally of the machine and relative to the table 39 sothat the point of the workpiece at which the bend 25 is to-be formed canbe varied with respect.

to the location at which the bend 24 is formed. To'permit thisadjustment the arms 56 and 51 of the main wing 5| are constructed so asto constitute ways on which the die carrier 86 is movable and havelongitudinal T-slots 8| therein with which the bolts-82 cooperate forlocking the die carrier in fixed relation on the main wing at thedesired position of adjustment. The auxiliary clamping die 50 issupported by another generally flat plate-like portion of the wing 53can also b conveniently referred to as a platen portion since it carriesthe bending die 46 and apduring the bending operation. These pivotmembers 85 and 86 are carried, respectively, by a pair of front and reararms 8! and 88 which are- 9 eiq a -n thgupper si 931 isses.

Compression rier'80. The auxiliary wing 53 is provided with a pair offront and rear rack elements 89 and 90 on the upper side thereof whichmesh with front and rear pinions or gear sectors 9| and 92 carried bythe pivot members 85 and 86, respectively. The pivot members 85 and 86are retained in the arms 81 and 88 by means of bolts 85 (see Figs. 2 and9) and are held against rotation by the keys 86 The gear sectors SI and92 are connected with the pivot members 85 and 86 by means of the bolts85 and are held from rotating relative to the pivot members by the keyelements 86 The bending die 46 is not mounted in fixed relation on theauxiliary wing 53 but is capable of substantially parallel slidingmovement relative thereto. For this purpose, the auxiliary wing 53 isprovided with a bearing plate 93 on which the auxiliary bending die 46is slidable during swinging of the auxiliary wing. The position of theauxiliary bending die 46 relative to the auxiliary wing 53 can beadjusted by means of suitable pressure screws 93* mounted in theauxiliary wing and which apply pressure to the under side of the bearingplate. The action of the screws 93 also holds the racks 89 and 90 inproper mesh with the gears 9i and 92.

The above-mentioned swinging movement is imparted to the main wing 5I bymeans of a gear sector 95 which is rigidly attached to the wing and adriving gear 96 meshing with such sector and driven by a shaft 91. Theshaft 91 extends transversely of the machine and is suitably journaledin the upright walls of the frame section I6. One end of the shaft 91extends beyond the upright rear wall of the frame section I6 and carriesa pinion 98 which is engaged by a vertically disposed power rack 99. Therack 99 is movable in a guideway I and is adapted to be actuated by adouble-acting power cylinder IN to which liquid or other suitable motivefluid under pressure is adapted to be supplied. The rack 99 is attachedto a piston rod I02 projecting from the lower end of the cylinder IOI sothat a power stroke of the cylinder in one direction will swing the mainwing I upwardly on the pivot members 63 and 64 to cause bending Of theworkpiece 43 around the die unit 2I and a power stroke of the cylinderIOI in the opposite direction will return the main wing to its initialposition, as shown in Figs. 2 and 5. The cylinder IOI can be suitablymounted on the frame section I6 in the substantially upright relationshown in the drawings. The main wing 52 is actuated in a similar mannerby another such power cylinder IOI mounted in upright relation on theframe section II.

The auxiliary wing 53 is adapted to be swun on the pivot members 85, 86and relative to the main wing 5| by a suitable power device carried bythe main wing. In this instance the power device for actuating thauxiliary wing 53 is a double-acting cylinder I04 to which liquid orother suitable motive fluid under pressure is adapted to be supplied.The auxiliary wing 53 has an actuating arm I05 rigidly connectedtherewith and to which actuating movement is supplied by the powercylinder I04. For this purpose, a bellcrank lever I06 is employed totransmit such motion to the auxiliary wing and has an arm portion I06pivotally connected with a piston rod I01 projecting from the powercylinder I04 and an arm portion I06 pivotally connected with theactuating arm I05 of the auxiliary wing by the pivot pin I08. Theconnection of the bellcrank lever I06 with the piston rod I01 can be"tion between this lever and the frame II.

made as an adjustable connection by providing a nut I09 on a threadedportion of the piston rod and to which nut the arm portion I06 ispivotally connected by the pivot pin means I I0.

Reverting now to the anvil die unit 2 I, it should be explained that thedie carrier 22 is of a substantially polygonal cross-sectional shape, inthis instance quadrangular, and has longitudinal slots. H2, H3, H4 andH5 formed therein in which the anvil die members 24, 25, 26 and 2! aredisposed, respectively. The slots H2, H3, II4 and H5 are located so asto extend along the corners of the die carrier 22 and form guideways inwhich the anvil die members 24, 25, 26, and 21 are movable in asubstantially radial direction with respect to th longitudinal axis ofthis die carrier. This radial movement of the anvil die members in thecarrier 22 renders the die unit expansible and contractable.

When the die unit 2| is in its initial position, that is-to say in theinoperative position spaced above the clamping dies 4I and 42 as shownin Fig. 3, the anvil die members 24, 25, 26 and 21 are in theirretracted position. When the die unit 2I is moved downwardly by the dieslide 20 to cause the anvil die members 24 and 26 to cooperate with theclamping dies M and 42 to clamp the intermediate portion of theworkpiece 43 therebetween, all of the anvil die members 24, 25, 26 and21 are in their projected or extending position as shown in Fig. 4. Whenthe die unit 2I is moved upwardly to its initial position after thebending of the workpiece 43 therearound, the anvil die members 24, 25,26 and 21 are again retracted and the resulting contracted condition ofthe die unit permits the polygonally shaped workpiece to be more readilyremoved therefrom by endwise axial movement of the formed Workpiecerelative to the die carrier 22.

The anvil die members 24, 25, 26 and 21 of the die unit 2I are extendedand retracted relative to the die carrier 22 by means of pairs of links24 25 26 and 21 which transmit pushing and pulling forces to the anvildie members in response to rotation of an actuating shaft I I6 relativeto the die carrier 22 in which this shaft is rotatably journaled. Theshaft II6 has front and rear drive plates I I1 and I I8 keyed thereto atlongitudinally spaced points, as shown in Fig. 8, and with which theanvil die members 24, 25, 26 and 21 are connected by the pairs of frontand rear links 24 25 26 and 21*. When the shaft H6 is rotated in acounterclockwise direction, as viewed in Fig. 1, the links 24*, 25 26and 21* will impart outward or expanding movement to the anvil diemembers 24, 25, 26 and 21, thereby shifting these members to theirextended position shown in Fig. 4 which corresponds with the expandedcondition of the die unit. When the shaft II6 is rotated in the oppositedirection, that is in a clockwise direction as viewed in Fig. 4, thelinks will be made to again assume their relative angular positionsshown in Fig. 1, thereby moving the anvil die members inwardly to theposition of Fig. 1 which corresponds with the contracted condition ofthe die unit 2 I.

The rotary movement for expanding and contracting the die unit 2I can beimparted to the shaft I I6 by any suitable power means, but in thisinstance the actuating movement imparted to the die slide 20 by thepower cylinder 30 is also used to cause such actuation of the shaft II6.For this purpose the shaft H6 is provided with an actuating lever H6 atits rear end and an actuating link II8 provides an operating connec-The - by such bar.

link I I8 has one end thereof pivotally connected means of the bar I28and an eye-bolt I2I carried The link I I8 has its upper end pivotallyconnected with the eye portion of the bolt I2I by means of the pivot pinI22. The bar I28 is connected with the frame II by means of one or morebolts I23 engaging in a T-slot I24 and providing for adjustment of thebar relative to the frame.

The workpiece 43 may be a strip-like sheetmetal member which is to bebent to a polygonal form, for example the quadrangular cross-sec tionalshape shown in Fig. 10. Usually the work piece 43 will have alongitudinal edge flange 43 extending along one or both side edgesthereof. During the bending operation which forms'the I bends 24 25 26and 2? the Web portion 43 of the workpiece is bent out of its own planeand the edge flanges 43 are bent within their own planes.

To prevent wrinkling or buckling of the edge flanges '43 during suchbending thereof the groups of clamping and bending dies ll, 45, 45, 48and 42, 41, 48, 58 are provided with angular por tions or flanges I25which cooperate with the end faces of the anvil die members 24, 25, 2Eand 2i in holding the edge flanges 43 of the workpiece against wrinklingor buckling during the bending -ofthe workpiece around such anvilmembers. .The angular portions I25 of the clamping and .45, 46, 41 and48, which die members are then in their initial position in which theyare in a substantially horizontally aligned relation longitudinally ofthe machine as shown in Figs. '1 and 2. The workpiece is at this timealso supported, in part, by the main and auxiliary clamping dies 4|, 49,42, and 58 which are then in aligned rela tion with the main andauxiliary bending dies.

The power cylinder 3| is then operated to move the anvil die unit ZIdownwardly into clamping cooperation with the main clamping dies 45 andThis downward movement of the die unit 2i causes the anvil die members24, 25, 25 and 21 thereof to be projected to their extended position, asexplained above, and also causes portions of the anvil die members 24and 26 to clamp corresponding portions of the workpiece 43 against themain clamping dies 4I and 42.

I The main wings 5i and 52are now swung upwardly by actuation of thepower cylinders i8! which impart downward movement to thepower 'and 52causes the main bending dies 45 and 41 to rock tangentially around theanvil die mem here 24 and 26, respectively, and to thereby bend .theworkpiece 43 around these anvil die members,

as shown'in Fig. 4, for forming the bends 24 and 26 'During the rockingof the main bending dies 45 and 41 around the anvil die members 24 and26, these bending dies are pressed against the workpiece and the rackelement Z, 3 for these 10 bending dies are maintained in mesh with thegear sectors 14, 15 by the pressure of the pressure rollers 66 acting onthe under side of the die plates 69 on which the bending dies and 41 aremounted. The engagement of the rack elements 12, 13 with the gearsectors 14, 15 also prevents skewing of the main bending dies orslipping of these dies relative to the work. During such rocking of themain bending dies 45 and 41 around the anvil die members 24 and 2'5, themain wings 5| and 52 also move relative to the bending dies so that thepoint of engagement of the pressure rollers 66 shifts on the die plates69 from the location shown in Figs. 1 and 5 to the location shown in'Fig. 4. The angular portions or flanges I25 of the main clamping andbending dies 4!, 45 and 42, 41 cooperate with'the end faces of the anvildie members 24 and 26 in holding the edge flanges 43 of the workpieceagainst buckling or wrinkling. Q

The upward swinging of the main Wings 55 and 52 to cause bending of theportions of the workpiece 43 around the anvil die members 24 and 25, asjust explained above, also causes the auxiliary clamping dies 49 and 50to be moved into clamping cooperation with portions of the anvil diemembers 25 and 21, respectively, so as to clamp portions of theworkpiece against the latterfas shown in Fig. 4. When the main wings 5!and 52 have been swung to their upward position, as shown in Fig. 4,they are maintained in this position and the auxiliary wings 53 and54are then swung toward each other and relative to the main wings tothereby actuate the auxiliary bending dies 46 and 48 and cause bendingof the end portions of the workpiece 43 toward each other and around theanvil die members 25 and 21 to form the bends 25 and 21 During thisswinging of the auxiliary wings 53 and 54, the auxiliary bending dies 46and 48 rock tangentially around the anvil die members 25 and 21,respectively, there by causing the end portions of the workpiece 43 tobe bent around these anvil die members. The above-described bends 24 and25 constitute the pair of bends produced by operation of the' main wing5| and of these bends the bend 24 can be referred to as the first bendand the band 25 as the second bend. Similarly the bends 28 and 21constitute the pair of bends produced by the main wing 52 and of thesebends the bend 25 can be designated the first bend and the bend 2i asthe second bend. g

The rack elements 89,89 for the auxiliary bending dies 46 and 48 are inmesh with the gear sec.- tor 9|, 92 and prevent skewing of the auxiliarybending dies or slipping of these dies relative to the workpiece. Sincethe auxiliary bending dies 46 and 48 are not rigidly connected to theauxiliary wings 53 and 54, but are slidable on the bearing plates 93carried by the auxiliary wings, it will be seen that relative slidingmovement will occur between the auxiliary bending dies and the auxiliarywings during this rocking of the auxiliary bending dies around the anvildie members 25 and 21. The extent of such relative sliding movement isillustrated in Fig. 4 for the auxiliary bending die 48.

During the bending of the workpiece accomplished by the auxiliarybending dies 45 and 48, that is to say during the forming of the bends25a and 21a, the angular portions I25 of the auxiliary bending diescooperate with the end faces of the anvil die members 25 and 21 forpreventing wrinkling or buckling of the edge flanges 43a of theworkpiece. The swinging of 11 the auxiliary wings 53 and 54 foractuating the auxiliary bending dies 46 and 48 during the bendingoperation and for returning these dies after the completion of thebending operation, is accomplished by the above-described powercylinders I04 which are carried by the main wings 5I and 52 and transmitsuch movement to the auxiliary wings through the bellcrank levers I05.

After the various portions of the workpiece have been bent around theanvil die members 24, 25, 26 and 21 to form the bends 24a, 25a, 26a and21a, as explained above, the auxiliary wings 53 and 54 are returned totheir initial position by the cylinders I04 and then the main wings SIand 52 are returned to their initial position by actuation of the powercylinders IiiI. lIhe workpiece 43 which has been bent to a polygonalcross-sectional shape, as shown in Fig. 9, remains on the anvil die unit2| in surrounding relation to the carrier 22 and the anvil die membersthereof. The power cylinder 3I is now actuated to impart upward movementto the die slid 2 and the anvil die unit ZI carried thereby. This upwardmovement of the die unit 2I causes retraction of the anvil die membersin the manner explained above, which permits the polygonally formedworkpiece to be withdrawn from the die unit 2| by endwise movementrelative thereto.

In connection with the operation of the machine IE! it should beunderstood that the main wings SI and 52 can be actuated simultaneouslyand likewise the auxiliary wings 53 and 54 can be actuatedsimultaneously. It is not necessary, however, that the main wings beactuated simultaneously nor that the auxiliary wings be ac tuatedsimultaneously and, if desired, the main wings can be actuated insuccession and the auxiliary wings can likewise be actuated insuccession. When the main and auxiliary wings are actuatedsimultaneously the bending operation can be performed in a shorter timeinterval but. on the other hand, when the main and auxiliary wings areactuated in succession a lighter load is imposed on the power mechanismof the machine.

As shown in the drawings the machine I rna include an auxiliary craneI28 comprising an upright post or standard I29 pivoted on the frame IIand a cantilever arm I30 having a trolley device or hoist I3I mountedfor longitudinal traveling movement thereon. The crane I28 can be usedfor handling formed workpieces or for handling the die unit 2i when thelatter is being mounted on, or removed from, the die slide 20.

It was mentioned above that the frame sec-- tions I6 and II areadjustably movable on the ways I4 and I to adapt the machine todifferent workpieces and to the formation of differently spaced bends inthe workpiece. Such shifting of the frame sections I6 and H can beaccomplished by providing the bed portion I2 of the frame with anadjusting screw I32 for each frame section and which cooperates with thethreaded opening of a depending bracket I33 carried by the framesection. When the frame sections I8 and I! have been shifted to thedesired adjustment by means of the screws I32, they are thereafterretained at the desired spacing by means of the links 76 and I1 and bythe use of any suitable clamping or holding means. It will beunderstood, of course, that links of a different length are substitutedin the machine to suit the adjusted spacing of the frame sections.

From the foregoing description and the accompanying drawings it will nowbe readily understood that this invention provides a machine forperforming multiple bends in an elongated metal workpiece as steps of asingle bending operation and that the improved machine carries out thisoperation with but one clamping of the workpiece and it is unnecessaryto shift the workpiece or reclamp the same as has been necessary in themachines heretofore available. It will also be seen that in thisimproved machine a metal workpiece can be quickly, accurately andeconomically bent to a desired polygonal cross-sectional shape and thatwhen the workpiece is a longitudinally flanged metal workpiece thisbending can be carried out without wrinkling or buckling of the flanges.Additionally, it will be understood that in this improved machine thebending dies are actuated, in part, by swinging main wings and, in part,by swinging auxiliary wings which are carried by the main wings. Fromthe foregoing detailed description it will also be understood that theanvil die unit is contractable to facilitate the removal of the formedworkpiece therefrom. Moreover, it will be understood that this improvedbending machine provides a bending die member which is adapted forsliding movement relative to a swinging wing by which such bending dieis actuated during the bending operation.

Although the improved bending machine has been illustrated and describedherein to a somewhat detailed extent, it will be understood, of course,that the invention is not to be regarded as being limitedcorrespondingly in scope, but includes all changes and modificationscoming within the terms of the claims hereof.

Having thus described my invention, I claim:

1. In a metal bending machine of the character described, a work supportadapted to receive thereon a workpiece to be bent, a die unit embodyinga plurality of anvil die members and being movable for bringing one ofsaid anvil die members into work-clamping cooperation with said worksupport, a wing mounted for swinging movement, a bending die carried bysaid wing and being rockable thereby around said one anvil die memberfor bending a portion of said workpiece therearound, a clamping diecarried by said wing and being movable thereby into work-clampingcooperation with another of said anvil die members, a second bending diecarried by said wing and being rockable around said other anvil diemember for bending another portion of said workpiece therearound,mounting means mounting said second bending die on said wing forswinging movement relative thereto for causing the rocking of saidsecond bending die around said other anvil die member, means forimparting said swinging movement to said wing, and a power device of thetype adapted to be energized for producing an actuating force andcarried by said wing and operably connected with the mounting means forsaid second bending die for imparting said swinging movement to thelatter.

2. In a metal bending machine of the character described, a worksupporting die adapted to receive thereon a workpiece having web andflange portions, a die unit embodying a plurality of anvil die membersand being movable for bringing one of said anvil die members intoworkclamping cooperation with said work support. a wing mounted forswinging movement, a bending die carried by said wing and being rockablethereby around said one anvil die member for forming a first bend in theworkpiece at one point thereof by bending the web portion of saidworkpiece out of its own plane and simultaneously bending the flangeportion within its own plane, said work supporting die and said bendingdie having angularly disposed portions for holding said flange portionof the workpiece against buckling during the forming of said first bend,a clamping die carried by said wing and being movable thereby intowork-clamping cooperation with another of said anvil die members,alsecond bending die carriedby said wing and being rockable around saidother anvil die member for forming a second bend in the workpiece atanother point thereof by bending said web portion out of its own planeand simultaneously bending said flange portion within its own plane,said clamping die and said second bending die having angularly disposedportions for holding said flange portion of the workpiece againstbuckling during the forming of said second bend, mounting means mountingsaid second bending die on said wing for swinging movement relativethereto,

means for imparting said swinging movement to said wing, and a powerdevice of the type adapted to be energized for producing an actuatingforce and carried by said wing and operably connected with the mountingmeans for said second bending die for imparting said swinging movementto the latter.

3. In a metal bending machine of the character described, a work supportadapted to receive thereon a workpiece to be bent, a die unit embodyinga plurality of anvil die members including a first pair of anvil diemembers and a second pair of anvil die members, said die unit beingmovable for bringing said first pair of anvil die members intowork-clamping cooperation with said work support, a pair ofwings-mounted for thereby into work-clamping cooperation with saidsecond pair of anvil die members, second bending dies carried by saidwings and being rockable around said second pair of anvil die membersfor bending other portions of said workpiece therearound, mounting meansmounting said second bending dies on said wings for work bending andreturn swinging movements relative thereto, means for imparting saidswinging movement to said wings, and double acting power devices of thetype adapted to be energized for producing actuating forces and mountedon said wings and operably connected with the mounting means for saidsecond bending dies for imparting said swinging movements to the latter.

4. In a metal bending machine of the character described, a work supportadapted to receive thereon a workpiece to be bent, a die unit embodyinga plurality of anvil die members including a first pair of anvil diemembers and a second pair of anvil die members, said die unit beingmovable for bringing said first pair of anvil die members intowork-clamping cooperation with said work support, a pair of wingsmounted for swinging movement, bending dies carried by said wings andbeing rockable thereby around said first pair of anvil die members forbending spaced portions of said workpiece therearound, clamping diescarried by said wings and being movable thereby into work-clampingcooperation with said second pair of anvil die members, second bendingdies carried by said wings and being rockable around said second pair ofanvil die members for bending other portions of said workpiecetheredescribed, work supporting die means adapted to receive thereon aworkpiece having web and flange portions, a die unit embodying aplurality of anvil die members including a first pair of anvil diemembers and a second pair of anvil die members, saiddie unit beingmovable for bringing said first pair of anvil die members intoengagement with said workpiece at spaced points thereof and intowork-clamping cooperation with said work supporting die means, a pair ofwings mounted for swinging movement, first bending dies carried by saidwings and being rockable thereby around said first pair of anvil diemembers for forming a pair of initial bends in said workpiece at saidspaced points thereof by bending the web portion of the workpiece out ofits own plane and simultaneously bending said flange portion within itsown plane, said work supporting die means and said first bending dieshaving angularly disposed portions for holding said flange portion ofthe workpiece against buckling during the forming of said initial bends,clamping dies carried by said wings and being movable thereby intoengagement with said workpiece at other spaced points and intoworkclamping engagement with said second pair of anvil .die members,second bending dies carried by said wings and being rockable around saidsecond pair of anvil die members for forming other bends in saidworkpiece at other points thereof by bendingsaid web portion out of itsown plane and simultaneously bending said flange portion within its ownplane, said clamping dies and said second bending dies having angularlydisposed portions for holding said flange portion of the workpieceagainst buckling during the forming of said other bends, mounting meansmounting said second bending dies on said wings for work bending andreturn swinging movements relative thereto, means for imparting saidswinging movement to said wings, and double act'- ing power devices ofthe type adapted to be energized for producing actuating forces andmounted on said wings and operably connected with the mounting means forsaid second bending dies for imparting said swinging movements to thelatter.

6. In a metal bending machine of the character described, worksupporting die means adapted to receive thereon a workpiece having weband flange portions, a die unit embodying by bending the web portion ofthe workpiece out of its own plane and simultaneously bending saidflange portion within its own plane, said work supporting die means andsaid first bending dies having angularly disposed portions for holdingsaid flange portion of the workpiece against buckling during the formingof said initial bends, clamping dies carried by said wings and beingmovable thereby into engagement with said workpiece at other spacedpoints and into work-clamping engagement with said second pair of anvildie members, second bending dies carried by said wings and beingrockable around said second pair of anvil die members for forming otherbends in said workpiece at other points thereof by bending said webportion out of its own plane and simultaneously bending said flangeportion within its own plane, said clamping dies and said second bendingdies having angularly disposed portions for holding said flange portionof the workpiece against buckling during the forming of said otherbends, mounting means mounting said second bending dies on said wingsfor work bending and return swinging movements relative thereto, meansfor imparting said swinging movement to said wings, and double actingfluid pressure responsive power devices carried by said wings andoperably connected with the mountings means for said second bending.dies for imparting said swinging movement to the latter.

'7. In a metal bending machine of the character described, a frame, awork support adapted to receive thereon a workpiece to be bent, a dieunit embodying a plurality of anvil die members one of which is adaptedfor work-clamping cooperation with said work support, a wing mounted forswinging movement, a bending die carried by said wing and being rockablethereby around said one anvil die member for bendinga portion of saidworkpiece therearound, a clamping die carried by said wing and beingmovable therebi, into work-clamping cooperation with another of saidanvil die members, a second bending die carried by said wing and beingrockable around said other anvil die member for bending another portionof said workpiece therearound, said second bending die being mounted onsaid wing for swinging movement relative thereto, means for impartingsaid swinging movement to said wing,

means for imparting said swinging movement to said second bending die, aslide on said frame and movable toward and away from said work support,said die unit comprising a carrier connected with said slide and onwhich said anvil die members are mounted for relative movement forcausing expansion and contraction of the die unit, means adapted toimpart such movement to said anvil die members, and means anchored onsaid frame and adapted to apply actuating thrust to the last-mentionedmeans for expanding said anvil die members in response to movement ofthe die unit into work-clamping cooperation with said work support andto contract said anvil die members in response to movement of the dieunit out of said work-clamping cooperation.

8. In a metal bending machine of the character described, a frame, awork supporting die adapted to receive thereon a workpiece having weband flange portions, a die unit embodying a plurality of anvil diemembers one of which is adapted for work-clamping cooperation with saidwork support, a wing mounted for swinging movement, a bending diecarried by said wing and being rockable thereby around said one anvildie member.

Ill

ror forming a first bend in the workpiece at one point thereof bybending the web portion of said workpiece out of its own plane andsimultaneously bending the flange portion within its own plane, saidwork supporting die and said bending die having angularly disposedportions for bolding said flange portion of the workpiece againstbuckling during the forming of said first bend, a clamping die carriedby said wing and being movable. thereby into work-clamping cooperationwith another of said anvil die members, a second bending die carried bysaid wing and being rockable around said other anvil die memher forforming a second bend in the workpiece at another point thereof bybending said web portion out of its own plane and simultaneously bendingsaid flange portion within its own plane; said clamping die and saidsecond bending die having angularly .disposed portions for holding saidflange portion of the workpiece against buckling during the forming ofsaid second bend, mounting means mounting said second bending die onsaid wing for swinging movement relative thereto, means for impartingsaid swinging movement to said wing, means for imparting said swingingmovement to said second bending die, a slide on said frame and movabletoward and away from said work supporting die, said die unit comprisinga carrier connected with said slide and on which said anvil die membersare mounted for relative movement for causing expansion and contractionof the die unit, means for causing such relative movement of said anvildie members, and means anchored on said frame and adapted to applyactuating thrust to the lastmentioned means for expanding andcontracting said anvil die members in response to movement of saiddieunit into and out of work-clamping cooperation with said work supportingdie. I

9. In a metal bending machine of the character described, a frame,'awork supporting die adapted to receive thereon a workpiece having weband flange portions, a die unit embodying a plurality of anvil diemembers one of which is adapted for work-clamping cooperation with saidwork support, a wing mounted for swinging movement, a bending diecarried by said wing and being rock- 'able thereby around said one anvildie member for forming a first bend in the workpiece at one pointthereof by bending the web portion of said workpiece out of its ownplane and simultaneously bending the flange portion within its ownplane, said work supporting die and said bending die having angularlydisposed portions for holding said flange portion of the workpieceagainst buckling during the forming of said first bend, a clamping diecarried by said wing and being movable thereby into work-clampingcooperation with another of said anvil die members, a second bending diecarried by said wing and being rockable around said other anvil diemember for forming a second bend in the workpiece at another pointthereof by bending said web portion out of its own plane andsimultaneously bending said flange portion within its own plane, saidclamping die and said second bending die having angularly disposedportions for holding said flange portion of the workpiece againstbuckling during the forming of said second bend, mounting means mountingsaid second bending die on said wing for swinging movement relativethereto, means for imparting said swinging movement to said wing, apower device carried by said wing and operably connected with thelast-mentioned mounting means for imparting said swinging r 17 movementto said second bending .die, a slide on said frame and movable towardand away from said work supporting die, said die unit comprising acarrier connected with said slide and on which said anvil die membersare mounted for relative movement for causing expansion and contractionof the die unit, means adapted to impart such movement to said anvil diemembers, and means anchored on said frame and adapted to apply actuatingthrust to the lastmentioned means for expanding said anvil die membersin response to movement of the die unit into work-clamping cooperationwith said work supporting die and to contract said anvil die members inresponse to movement of the die unit out of, said work-clampingcooperation.

10. In a metal bending machine of the character described, a frame, worksupporting die means adapted to receive thereon a workpiece having weband flange portions, a die unit embodying a plurality of anvil diemembers including a first pair of anvil die members adapted forwork-clamping cooperation with said work supporting die means and asecond pair of anvil die members, a slide operable on said frame andmounting said die unit for movement for bringing said first pair ofanvil die members into engagement with said workpiece at spaced pointsthereof and into work-clamping cooperation with said work supporting diemeans, a pair of wings mounted for swinging movement, first bending diescarried by said wings and being rockable thereby around said first pairof anvil die members for forming a pair of initial bends in saidworkpiece at said spaced points thereof by bending the web portion ofthe workpiece out Of its own plane and simultaneously bending saidflange portion within its own plane said work supporting die means andsaid first bending dies having angularly disposed portions for holdingsaid flange portion of the workpiece against buckling during the formingof said initial bends, clamping dies carried by said wings and beingmovable thereby into engagement with said workpiece at other spacedpoints and into work-clamping cooperation with said second pair of anvildie members, second bending dies carried by said wings and beingrockable around said second pair of anvil die members for forming otherbends in said workpiece at other points thereof by bending said webportion out of its own plane and simultaneously bending said flangeportion within its own plane, said clamping dies and said second bendingdies having angularly disposed portions for holding said flange portionof the workpiece against buckling during the forming of said otherbends, means mounting said second bending dies on said wings forswinging movement relative thereto, means for imparting said swingingmovement to said wings, power devices mounted on said wings and operablyconnected with the last-mentioned mounting means for imparting saidswinging movement to said second bending dies, said die unit comprisinga carrier connected with said slide and on which said anvil die membersare mounted for relative movement for causing expansion and contractionof the die unit, means adapted to move said anvil die members in adirection to expand or contract said die unit, and means anchored onsaid frame and adaptedto apply actuating thrust to the last-mentionedmeans for expanding and contracting said anvil die members in responseto movement of said die unit into and out of work-clamping cooperationwith said work supporting die means.

11. In a metal bending machine of the character described, a frame, awork support on said frame and adapted to receive thereon a workpiece tobe bent, a die unit embodying a plurality of anvildie members and beingmovable on said frame for bringing one of said anvil die members intowork-clamping cooperation with said work support, a wing pivoted on saidframe for swinging movement relative to said die unit, gear sectors onsaid frame and located substantially on the aXis of the wing pivot, adie plate having a bending die thereon and adapted to be actuated bysaid wing to cause rocking of said bending die around said one anvil diemember for bending said workpiece therearound, racks on said die platemeshing with said gear sectors, a'pressure roller carried by said wingand acting on said plate in a direction to retain said racks and gearsectors in mesh, clamping die means carried by said wing and beingmovable thereby into workclamping engagement with another of said anvildie members, a second die plate, a second bending die carried by saidsecond die plate and being movable thereon, means pivotally mountingsaid second die plate on said wing and adapting said second die plate tocause rocking of said second bending die around said other anvil diemember for bending another portion of said workpiece around the latter,other gear sectors carried by said wing and located substantially on thepivot axis of said second die plate, racks connected with said secondbending die and meshing with said other gear sectors, means forimparting said swinging movement to said wing, and means for impartingsaid swinging movement to said second die plate.

12. A bending machine of the character described comprising, a framehaving a work support adapted to receive thereon a workpiece to be bent,anvil die means adapted for work-clamping cooperation with said worksupport, a main wing pivoted on said frame for swinging movement, abending die rockable around said anvil die means by the swinging of saidmain wing for bending a portion of said workpiece around said anvil diemeans, means for imparting said swinging movement to said main wing, anauxiliary wing carried by said main wing and pivotally connectedtherewith for swinging. movement relative thereto, a, second bending diecarried by said auxiliary wing and being rockable around said anvil diemeans by the Swinging of said auxiliary wing for bending another portionof the workpiece around said anvil die means, and a double acting powerdevice of the type adapted to be energized for producing actuatingforces and mounted on said main wing and operably connected with saidauxiliary wing for imparting swinging movements to the latter.

13. A bending machine of the character described comprising, a framehaving a clamping die adapted to receive thereon a workpiece having weband flange portions, anvil die means adapted for work-clampingcooperation with said clamping die, a main wing pivoted on said framefor swinging movement, a bending die rockable around said anvil diemeans by the swinging of said main wing for bending a portion of saidworkpiece around said anvil die means by bending said web'portion out ofits own plane and simultaneously bending said flange portion within itsown plane, means for imparting said swinging movement to said mainwing,saidclamping die and said bending die having angularly disposed portionsfor holding said flange portion of the workpiece against buckling duringthe bending thereof, a second clamping die carried by said main wing andadapted for work-clamping cooperation with said anvil die means, anauxiliary wing carried by said main wing and pivotally connectedtherewith for swinging movement relative thereto, a second bending diecarried by said auxiliary wing and being rockable around said anvil diemeans by the swinging of said auxiliary wing for forming a second bendin the workpiece by bending the web portion thereof out of its own planeand simultaneously bending said flange portion within its own plane,said second clamping die and said second bending die having angularlydisposed portions for holding said flange portion of the workpieceagainst buckling during the forming of said second bend, and a powerdevice of the double acting pressure fluid responsive cylinder typemounted on said main wing and operably connected with said auxiliarywing for imparting swinging movements to the latter.

1%. A bending machine of the character described comprising, a framehaving a work support adapted to receive thereon a workpiece to be bent,anvil die means adapted for work clamping cooperation on said worksupport, a pair of main wings pivoted on said frame for swingingmovement toward said anvil die means from opposite sides thereof,bending dies rockable around said anvil die means by the swinging ofsaid main wings for bending different portions of said workpiece aroundsaid anvil die means, means for imparting said swinging movement to saidmain wings, auxiliary wings carried by said main wings and pivotallyconnected therewith for swinging movement toward said anvil die means,other bending dies carried by said auxiliary wings and being rockablearound said anvil die means by the swinging of said auxiliary wings forbending other portions of the workpiece around said anvil die means, anddouble acting power devices of the type adapted to be energized forproducing actuating forces and mounted on said main wings and operablyconnected with said auxiliary wings for imparting swinging movements tothe latter.

15. A bending machine of the character described comprising, a framehaving a work support adapted to receive thereon a workpiece to be bent,anvil die means adapted for work clamping cooperation with said worksupport, a main wing pivoted on said frame for swinging movement, abending die rockable around said anvil die means by the swinging of saidmain wing for bending a portion of said workpiece around said anvil diemeans, means for imparting said swinging movement to said main wing,said main wing having ways formed thereon, a clamping die carriermounted on said main wing and being adjustable thereon along said ways,a clamping die on said clamping die carrier and being movable intowork-clamping cooperation with said anvil die means by said swinging ofthe main wing, an auxiliary wing pivotally connected with said clampingdie carrier for swinging movement relative to port adapted to receivethereon a workpiece to be bent, anvil die means adapted for workclamping cooperation with said work support, a main wing pivoted on saidframe for swinging movement, a bending die rockable around said anvildie means by the swinging of said main wing for bending a portion ofsaid workpiece around said anvil die means, arcuate gear elements onsaid frame, racks connected with said bending die and meshing with saidarcuate gear elements, means for imparting said swinging movement tosaid main wing, said main wing having ways thereon, a clamping diecarrier on said main wing and ad- J'ustable to different positions alongsaid ways, a clamping die mounted on said clamping die carrier andmovable to work-clamping cooperation with said anvil die means by saidswinging of said main wing, an auxiliary Wing pivotally connected withsaid clamping die carrier and adapted for swinging movement relative tosaid main wing, a second bending die carried by said auxiliary wing andbeing rockable around said anvil die means by the swinging of saidauxiliary wing for bending another portion of the workpiece around saidanvil die means, arcuate gear elements on said clamping die carrier,racks connected with said second bending die and meshing with thearcuate gear elements of said clamping die carrier, and a power devicemounted on said main wing and operably connected with said auxiliarywing for imparting said swinging movement to the latter.

1']. A bending machine of the character described comprising, a framehaving a work support adapted to receive thereon a workpiece to be bent,anvil die means adapted for work clamping cooperation with said worksupport, a main wing pivoted on said frame for swinging movement, abending die rockable around said anvil die means by the swinging of saidmain wing for bending a portion of said workpiece around said anvil diemeans, means for imparting said swinging movement to said main wing, anauxiliary wing carried by said main wing and pivotally connectedtherewith for swinging movement relative thereto, a second bending diecarried by said auxiliary wing and being rockable around said anvil diemeans by the swinging of said auxiliary wing for bending another portionof the workpiece around said anvil die means, bearing means mountingsaid second bending die on .said auxiliary wing for sliding movementrelative thereto during said swinging movement of said auxiliary wing,and a power device mounted on said main wing and operably connected withsaid auxiliary wing for imparting said swinging movement to the latter.

18. In a bending machine, a frame having a work support adapted toreceive thereon a workpiece to be bent, an anvil die means movable toand from work-clamping cooperation with said main wing, a second bendingdie carried by said work support, a pair of main wings pivoted on saidframe for swinging movement toward said anvil die means from oppositesides thereof, a pair of auxiliary wings pivotally connected with saidmain wings and adapted for swinging movement toward said anvil diemeans, bending dies carried by said main wings and said auxiliary wingsand adapted to be actuated thereby for bending different portions ofsaid workpiece around the anvil die means, said anvil die means beingexpandable during movement thereof toward its work-clamping position andbeing contractable during movement thereof away from its work-clampingposition to permit removal of the bent workpiece, means for causing suchexpansion and contraction of said anvil die means,

"power means for actuating said main wings, and

double acting power devices of the type adapted to be energized forproducing actuating forces and mounted on said main wings and operablyconnected with said auxiliary wings for actuating the latter.

19. In a bending machine, a frame having a work support adapted toreceive thereon a workpiece to be bent, an anvil die means ofsubstantially polygonal shape movable relative to said work support formoving one side of the anvil die means into and out of work-clampingcooperation with said work support, a pair of main wings pivoted on saidframe for swinging movement toward each other and toward said anvil diemeans from opposite sides of the latter, a

pair of auxiliary Wings pivotally connected with said main wings andadapted for swinging movement toward the side of said anvil die meanswhich is opposed to the side having said workclamping cooperation withsaid support, bending dies carried by said main wings and said auxiliarywings and adapted to be actuated thereby for bending different portionsof said workpiece around the anvil'die means to cause said workpiece toassume the polygonal shape of said anvil die means, bearing meansmounting certain of said bending dies on said auxiliary wings forsliding movement relative thereto during the bending of said workpiece,said anvil die means being contractable during movement thereof awayfrom its work-clamping position to permit removal of the polygonallyformed workpiece therefrom, means for causing such contraction of saidanvil die means, power means for actuating said main wings, and powerdevices mounted on said main wings and operably connected with saidauxiliary wings for actuating the latter.

20. In a, metal bending machine of the character described, a frame, awork support on said frame and adapted to receive thereon a workpiece tobe bent, a die unit embodying a plurality of anvil die members and beingmovable on said frame for bringing one of said anvil die members intowork-clamping cooperation with said work support, a wing pivoted on saidframe for swinging movement relative to said die unit, gear sectors onsaid frame and located substantially on the axis of the wing pivot, adie platehaving a bending die thereon and adapted to be actuated by saidwing to cause rocking of said bending die around said one anvil diemember for bending said workpiece therearound, racks on said die platemeshing with said gear sectors, a pressure 22 roller carried by saidwing and acting on said plate in a direction to retain said racks andgear sectors in mesh, clamping die means carried by said Wing and beingmovable thereby into workclamping engagement with another of said anvildie members, a second die plate, a second bending die carried by saidsecond die plate and being movable thereon, means pivotally mountingsaid second die plate on said wing and adapting said second die plate tocause rocking of said second bending die around said other anvil diemember for bending another portion of said workpiece around the latter,other gear sectors carried by said wing and located substantially on thepivot axis of said second die plate, racks connected with said secondbending die and meshing with said other gear sectors, means forimparting said swinging movement to said wing, means for imparting saidswinging movement to said second die plate, said die unit comprising acarrier on which said anvil die members are mounted for relativemovement for causing expansion and contraction of the die unit, andmeans adapted to move said anvil die members in a direction to expandsaid die unit in response to movement of the die unit into work-clampingNumber cooperation with said work support and to move said anvil diemembers in a direction to contract said die unit in response to movementof the die unit out of said work-clamping cooperation.

LEE B. GREEN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS FOREIGN PATENTS Country Date Germany Feb. 14, 1929Number

